ulipristal and ulipristal-acetate

Vaginal ring delivery of selective progesterone receptor modulators (SPRMs) is under development to address the limitations of current hormonal methods that affect use and effectiveness. This method would be appropriate for use in women with contraindications to, or preferences to avoid, estrogens. A contraceptive vaginal ring (CVR) also eliminates the need for daily dosing and therefore might improve the effectiveness of contraception. The principal contraceptive effect of SPRMs is the suppression of ovulation. One limiting factor of chronic SPRM administration is the development of benign endometrial thickening characterized as PRM-associated endometrial changes. Ulipristal acetate (UPA) is approved for use as an emergency contraceptive pill, but no SPRM is approved for regular contraception. The Population Council is developing an ulipristal acetate CVR for regular contraception. The CVR studied is of a matrix design composed of micronized UPA mixed in a silicone rubber matrix The target product is a ring designed for continuous use over 3 months delivering near steady-state drug levels that will suppress ovulation. Results from Phase 1 and 2 studies demonstrate that suppression of ovulation occurs with UPA levels above 6-7 ng/mL.

Topics: Contraception; Contraceptive Agents, Female; Contraceptive Devices, Female; Female; Humans; Norpregnadienes; Receptors, Progesterone

To evaluate the efficacy and safety of ulipristal acetate as emergency contraception in women presenting 48-120 hours after receiving ulipristal acetate for unprotected intercourse.. Women aged 18 years or older with regular cycles who presented for emergency contraception 48 to 120 hours after unprotected intercourse were enrolled in 45 Planned Parenthood clinics and treated with a single dose of 30 mg ulipristal acetate. Pregnancy status was determined by high-sensitivity urinary human chorionic gonadotropin testing and return of menses.. A total of 1,241 women were evaluated for efficacy. Twenty-six were pregnant at follow-up, for a pregnancy rate of 2.1% (95% confidence interval 1.4-3.1%). These results satisfy the protocol-defined statistical criteria for success because the pregnancy rate was lower than both the estimated expected pregnancy rate and a predefined clinical irrelevance threshold. In addition, efficacy did not decrease over time: pregnancy rates were 2.3% (1.4-3.8%), 2.1% (1.0-4.1%), and 1.3% (0.1-4.8%) for intervals of 48 to 72 hours, more than 72 to 96 hours, and more than 96 to 120 hours, respectively. Adverse events were mainly mild or moderate, the most frequent being headache, nausea, and abdominal pain. Cycle length increased a mean of 2.8 days, whereas the duration of menstrual bleeding did not change.. Ulipristal acetate is effective and well-tolerated for emergency contraception 48-120 hours after unprotected intercourse.. II.

Topics: Contraception, Postcoital; Contraceptives, Postcoital, Hormonal; Female; Humans; Menstrual Cycle; Norpregnadienes; Pregnancy